Levels Of Various Proteins Research Articles

Early Dietary Protein Restriction and Intermittent Lighting.: 2. Effects on Carcass Characteristics of Male Turkeys

A trial was conducted to determine the effects of dietary protein restriction at an early age and intermittent lighting, designed for curtain-sided houses, on the carcass characteristics of Nicholas commercial male turkeys (sired by male Line 88). Four isocaloric diets containing various levels of protein (100, 90, 80, or 70% of control values) were fed ad libitum from 8 to 56 days of age. All birds were fed control diets from 1 to 7 days of age and from 57 to 124 days of age. Two lighting regimens, a control of 15 h light (L):9 h dark (D), and intermittent (15L:2D:1.5L:2D:1.5L:2D), were each assigned randomly to two rooms from Day 8 until the end of the study.Turkeys reared in intermittent lighting had heavier weights for whole breast (muscle and bone, P < .06) and breast muscle (without bone, P < .07) than those of the control (15L:9D) photoperiod. Toms fed the 90% protein diet in both lighting regimens had carcass part weights and yields similar to the controls. The weight of the breast and breast muscle and the percentage yield of breast and breast muscle decreased in birds fed the 80 and 70% CP diets. It is concluded that Nicholas commercial male turkeys can be reared in intermittent lighting and can be fed dietary protein levels at 90% of the control level from 8 to 56 days of age without negatively affecting the weights or yields of carcass parts.

Association between Neutrophil Concentration in Bronchoalveolar Lavage Fluid and Recent Losses in Diffusing Capacity in Men Formerly Exposed to Asbestos

It has been observed widely that some individuals exposed to asbestos will experience continued losses of lung function after asbestos exposure ceases. Unfortunately, there are few data on factors that determine clinical course, limiting the clinician's ability to determine prognosis in an individual case and restricting the possibility for testing or targeting any potential intervention to alter the course among the millions at risk. In an attempt to address this question, we studied a volunteer population of 50 such men from among a stable, heterogeneous population of asbestos-exposed workers who had been continuously followed in our occupational medicine clinics for up to 12 years (mean, 6.3 years); most had some clinical or roentgenographic sign of asbestos effect, pleural or parenchymal. Each subject was reexamined clinically, functionally, and roentgenographically. Asbestos and tobacco exposure histories were carefully reviewed with the subjects and quantified based on these reports and available data regarding the various work environments from which they came. Subsequently, each underwent a bronchoalveolar lavage to assess cellularity and levels of various proteins. The levels of risk factors, clinical findings, and biologic parameters from lavage were examined for their relationship to serial changes in lung function during the period over which they had been previously followed. Results of the study demonstrate that serial changes in lung function were not closely related to level or length of prior exposure, smoking behavior, chest roentgenographic findings, or lung volumes. Progressive loss of diffusing capacity for carbon monoxide (Dco) was significantly associated with two factors: level of neutrophil concentration in lavage fluid (0.043 +/- 0.016 ml/min/mm Hg/yr drop for each 0.1 x 10(4) neutrophils per milliliter, p = 0.02) and the level of Dco itself (0.17 +/- 0.07 ml/min/mm Hg/yr drop for each 10 percent decrease in percent Dco predicted, p = 0.01). The relationship with neutrophil concentration was statistically independent of the association with Dco itself and stronger; it persisted when loss of Dco was adjusted for baseline value. Lung volume changes were not associated with any predictor variables, alone or in combination. We conclude that the presence of neutrophils in bronchoalveolar lavage fluid is associated with recent disease progression that may have implications in studies of the mechanisms of asbestos-associated disease and in clinical treatment of patients at risk.

Effect of histamine on collagen and collagen m-RNA production in human skin fibroblasts

Direct effects of histamine on collagenous and non-collagenous protein synthesis by human skin fibroblasts were studied. Fibroblasts derived from human skin were incubated with various concentrations of histamine. Collagen and non-collagenous protein synthesis were measured by incorporation of 3H-proline. Both collagen synthesis measured as protein-bound hydroxyproline and non-collagenous protein synthesis measured as protein-bound proline increased in the presence of histamine at concentrations of 10 1–10 2 μg/ml. Total RNA was extracted and m-RNA levels of various proteins were estimated by dot blot analysis, and densitometrically quantified. The levels of α 1( I) collagen and β-actin m-RNA were clearly increased at the same concentrations. m-RNA levels of α 1( III) collagen were also increased but the rate was lower than that of α 1( I) collagen. No alteration of β-tubulin m-RNA level was observed at the same concentrations. These results demonstrate that stimulation of collagen synthesis by histamine is pretranslationally controlled.

Insulin-like growth factor binding proteins in rats respond to fasting and the protein and energy content of the re-feeding diet

We investigated the effects of fasting and re-feeding various levels of protein and energy on serum levels of specific insulin-like growth factor binding proteins (IGFBPs) and serum IGF-I binding activity patterns in rats. Fasting (48 hr) caused serum IGF-I levels to decrease 62% from 400 ng/mL to 151 ng/mL ( P < 0.05). Re-feeding fasted animals (48 hr) a low protein-low energy diet (control diet, intake 66% lower than re-fed control group) maintained IGF-I at fasted levels whereas re-feeding a low protein-isocaloric (5% protein, energy-adequate) diet caused IGF-I levels to drop 50% below fasted levels to 76 ng/mL ( P < 0.05). IGF-I binding activity in the 155K region paralleled serum IGF-I levels. Fasting caused a 150% increase in IGF-I binding activity in the 40K region. Re-feeding a control diet restored both peaks of IGF binding activity to baseline levels. IGF binding activity in the 40K region of rats re-fed a low protein-isocaloric diet increased 60% above fasting (over 200% above control). Energy level with protein restriction was important since responses in both IGF binding peaks were greater in low proten-isocaloric than low protein-low energy re-fed groups. Ligand blotting revealed that protein restriction at both energy levels caused the 38–45K bands (IGFBP-3) to decrease, and the 32K band (IGFBP-1) to increase compared to baseline, fasted, or re-fed control levels. Signal intensity of the IGFBP 24K band was lower in fasted and low protein-low energy rats compared to groups receiving adequate energy. Thus, that IGFBPs are differentially regulated and acutely responsive to nutritional manipulations suggests that the IGFBPs may be markers of acute changes in nutritional status.

Response Surface Approach to Studying the Protein and Energy Requirements of Laying Hens

Two experiments were conducted with hens from 20 to 44 wk of age housed in cages. There were 384 hens in Experiment 1 and 360 hens in Experiment 2. The hens were fed various levels of protein and energy in a factorial arrangement in Experiment 1 and in a central composite rotatable design in Experiment 2. The diets contained primarily ground corn, soybean meal, wheat middlings, and poultry oil. Production responses to dietary protein and MEn were found to be nonlinear in nature and thus conformed to the law of diminishing marginal returns. Protein by MEn interactions, when significantly different from zero, were small in magnitude. Variability in hen performance (as measured by hen-day egg production, feed consumption, egg weight, and body weight gain) could be described better by using dietary protein and energy levels than the energy to protein ratio.

Protein and Energy Relationships in the Diet of the American Alligator (Alligator mississippiensis)

First-year alligators (Alligator mississippiensis) averaging 377-857 g body weight were fed diets containing various levels of protein, fat and carbohydrate. In experiment 1, nine diets arranged in a centrally rotatable composite design contained 0-36% extruded corn and 4-20% total fat. Response surface analysis predicted maximum responses in performance criteria at 6.3-18.8% corn and 15.8-27.4% fat. Corn inclusion at up to 27-36% of diet resulted in equal or improved performance compared to carbohydrate-free diets of equal fat content. Energy digestibility averaged 84.3%. Protein digestibility averaged 86.7%. Maximum responses in performance criteria were predicted at 42.5-48.7% digestible protein and 4367-4421 kcal/kg digestible energy. In two additional experiments, alligators were either fasted or fed for various numbers of days/week. Carbohydrate-supplementation of high protein diets led to equal or significantly improved performances. Performance was maximized by feeding the alligators 5-6 d/w. Regression of body weight changes against energy and protein intake yielded estimates of daily maintenance requirements of 5.7-8.4 kcal and 0.49-0.89 g protein/kg live body weight. Dietary fat and carbohydrate in the forms and amounts fed to young alligators were well-utilized. Optimal digestible energy:crude protein ratios (8.2-10.9:1 kcal/g protein) were similar to those of other aquatic ectotherms of equal size.

The Influence of Dietary Tryptophan on Broiler Chick Growth and Lipid Metabolism as Mediated by Dietary Protein Levels

Three experiments were conducted to determine how dietary protein and tryptophan influence the lipid metabolism of growing broiler chicks. A diet-dilution method (corn-com gluten meal-gelatin summit/corn starch basal) was used in three factorial experiments. Various levels of protein and tryptophan were fed in each experiment: protein from 16 to 28% and tryptophan from .34 to 2.74% of protein.Gain was maximized when the dietary levels of tryptophan were .83 ± .03, .77 ± .04, .77 ± .05, and .78 ± .05% of the protein for 16, 20, 24, and 28% dietary protein, respectively. The requirement estimates for feed efficiency and gain were similar. Liver lipids significantly decreased as the level of dietary tryptophan increased at each protein level (P<.0001). Dietary tryptophan did not significantly alter the concentration of total plasma lipid in the chicks or in die carcass lipid content (P>.2399). Tryptophan supplementation significantly increased the concentration of plasma linoleic acid and plasma free tryptophan.The requirement of the chicks for tryptophan was estimated to be .80 ± .01% of the dietary protein for the growing chick. Increased liver lipid and decreased plasma tryptophan are diagnostic lesions suggesting a tryptophan deficiency.

Quantitation of Plasma Levels of Tetranectin - Effects of Oral Contraceptives, Pregnancy, Treatment with L-Asparaginase and Liver Cirrhosis

Tetranectin is a tetrameric protein that binds to kringle 4 of plasminogen. Increase of electrophoretic mobility of the otherwise slowly migrating tetranectin in the presence of ethylenediaminetetraacetate was used to develop a reproducible electroimmunoassay to quantify plasma levels. Plasma levels in normals were found within narrow limits of 100 +/- 16 (SD)%, (100% = 0.15 mumol/l). There was no difference between males and females, smokers and non-smokers, and there were no significant changes with age from 20 to 49 years. Patients with severe liver cirrhosis showed a large variation in plasma tetranectin levels but no systematic or average reduction, in contrast to strong reductions in plasma levels of other proteins. Patients treated with L-asparaginase showed a gradual reduction in time in plasma levels of various proteins, though tetranectin showed no significant reduction. It is concluded that tetranectin can be assayed reproducibly in plasma and has a well regulated plasma level. This level is not sensitive to conditions with reductions in synthesis of many proteins, such as during cirrhosis of the liver and during L-asparaginase therapy. The reductions in plasma levels during the use of oral contraceptives and pregnancy indicate involvement of sex steroids in the metabolism of tetranectin.

Effect of donor age on the levels of activity of rat, hamster and human liver S9 preparations in the Salmonella mutagenicity assay.

Liver S9 fractions were prepared from male and female Syrian Golden hamsters and Sprague-Dawley rats, 1, 3, 6 and 12 months of age, which were either uninduced (corn-oil treated) or induced with Aroclor 1254 suspended in corn oil. These preparations were compared at varying protein levels for their ability to metabolize polycyclic aromatic hydrocarbons (benzo(a)pyrene, 3-methylcholanthrene, 7,12-dimethylbenzanthracene), aromatic amines (N-2-acetyl-aminofluorene, beta-naphthylamine, benzidine), and nitroso compounds (N-nitroso-diethylamine, nitrosopyrrolidine, nitrosodiethylmethylurea) to products mutagenic to Salmonella typhimurium. With 3-methylcholanthrene or benzo(a)pyrene in the presence of S9 preparations from Aroclor-treated male rats, the numbers of revertant colonies decreased with increasing age of the animals. Mutagenicity of aromatic amines was not affected by the age of the donor animals from which the S9 was prepared. The use of liver S9 from 1-month-old hamsters produced the highest number of revertant colonies with nitrosodiethylamine. This number decreased with preparations from animals of increasing age. The greatest number of revertant colonies with nitrosopyrrolidine occurred with preparations from male hamsters. A decrease in numbers of revertant colonies with increasing age was observed with the S9 preparation from Arcolor-treated male rats. Nitroso-diethylmethylurea was mutagenic only in the presence of S9 from male or female Aroclor-treated hamsters and the metabolic activity of the S9 preparations did not change with age. S9 preparations from livers of 50-70-year-old humans were compared for their ability to produce mutagenic metabolites at a number of protein levels.(ABSTRACT TRUNCATED AT 250 WORDS)

EFFECTS OF DIET AND SIZE ON GROWTH, FEED DIGESTIBILITY AND DIGESTIVE ENZYME ACTIVITIES OF THE MARINE SHRIMP,Penaeus setiferusLINNAEUS

ABSTRACTRelationships between protein level, size, apparent feed digestibility, digestive enzyme activities and growth ofPenaeus setiferuswere investigated during a 30‐day growth trial. Small (3.7 g), medium (9.5 g), and large (14.7 g) shrimp were fed four isocaloric diets with varying protein levels. Apparent total dry matter digestibilities and apparent protein digestibilities were determined for small and medium shrimp. General and acid protease, trypsin, carboxypeptidase A and B, amylase, chitinase, non‐specific esterase and lipase activities were also assayed for small and medium shrimp.Shrimp survival was unrelated to diet or size. Instantaneous growth rate, total dry matter and protein digestibilities decreased as shrimp size increased. Small shrimp fed the 22% protein diet grew the least but exhibited the highest enzyme activities, especially carbohydrases. Small shrimp fed the 38% protein diet displayed the highest dry matter digestibility. Medium shrimp fed the 30% protein diet exhibited the lowest survival and growth while medium shrimp fed the 22% protein diet exhibited the highest enzyme activities. Higher digestive enzyme activities on the 22% protein diet may be evidence of an adaptation to a diet containing less digestible proteins.

Quantitative Changes in In Vitro and In Vivo Protein Synthesis in Aging and Rejuvenated Soybean Cotyledons

Cotyledons of light-grown soybean (Glycine max L. var Wayne) seedlings were used as a model system to study the possibility that aging requires qualitative changes in protein synthesis. Cotyledons reached a final stage of senescence and then abscised about 22 days after imbibition. Cotyledon senescence was reversed at 20 days after germination by epicotyl removal. Thereafter, the cotyledons regained much of the chlorophyll, RNA, protein, and polyribosomes lost during aging.Total poly(A)mRNA was extracted from 4-, 12-, 20-day-old, and rejuvenated cotyledons and translated in a wheat germ system. Comparison of translation products on two-dimensional O'Farrell gels showed that many translation products increased in quantity during aging, while roughly half as many decreased. Rejuvenation returned the translation products to approximately 4-day-old levels in roughly half of those products which were diminished with age. Conversely, almost one-third of the products which had increased with age decreased with rejuvenation. None of the translation products were totally lost nor were newly synthesized products detected during aging. Therefore, aging in this system probably does not involve complete gene repression or depression. The observation that epicotyl removal causes a reversal in the levels of various proteins synthesized in vitro was corroborated by similar observations following in vivo labeling of cotyledon sections and analysis by SDS-polyacrylamide gel electrophoresis and fluorography. Densitometric scans of fluorograms revealed a gradual shift in profiles of both in vitro and in vivo translation products during aging. Rejuvenated cotyledon proteins had a profile resembling that of 4-day-old cotyledons. The overall level of [(35)S]methionine incorporation into protein in vivo declined gradually during aging but was restored to 4-day-old levels within 2 days after epicotyl removal.

Technical aspects and complications of plasma-exchange.

Technical aspects including technology for plasma-exchange, anticoagulation, blood access and blood substitutes are reviewed. The consequences of exchange on the level of various proteins are analyzed considering especially their role in coagulation disorders and immunomodulation. The complications which have been published and those which have been the result of a French inquiry are extensively analyzed. The mortality in this later experience is around 1% represented by non-cardiac pulmonary edema and cardiac circulatory failure. The factors which can reduce hazards are reviewed.

Control of Hepatic Utilization of Serine, Glycine and Threonine in Fed and Starved Rats

Effects of varying protein level on hepatic utilization of serine, threonine and glycine were examined by measurements of metabolic fluxes across the liver. Feeding a high protein (HP) diet markedly enhanced hepatic extraction of serine, threonine and glycine, in parallel to alanine. After 20 hours starvation, activity of alanine aminotransferase and serine dehydratase still reflected the induction of these enzymes in fed rats. Thus, in starved rats previously adapted to HP diets, hepatic uptake of serine, threonine and glycine remained very efficient. With a normal diet, gluconeogenesis from alanine may be very active during starvation, in contrast to serine. The present results suggest that serine, and, to a lesser extent glycine, are very efficient glucogenic substrates with HP diets. The serine aminotransferase pathway might be important in rats fed HP diets, particularly for utilization of serine synthesized from glycine in mitochondria. With HP diets, the drop in hepatic alanine, serine and threonine suggest that transport across the plasma membrane might limit their utilization.

Variations in Daily Urinary-N of Adult Rats on Varying Protein Levels

The pattern of daily fluctuations in urinary nitrogen (UN) of adult male albino rats fed on varying protein levels was studied. In the first experiment, two protein levels (7% and 13%) were provided, using two rats at each level for 10 weeks. In the second experiment, a submaintenance protein level (4%) was added, and finally, an excess protein level (30%) was tested on two rats. Time series analysis was used to study the underlying pattern of daily fluctuations in the UN of adult rats maintaining body weights on a near constant intake. It is shown that the behavior of daily fluctuations as reflected by serial correlation is in fact affected by the protein level fed. It was observed that on the 7% and 13% levels, the serial correlations were significant and the process could be identified as an autoregressive process of order one. At very low (4%) as well as very high (30%) levels of protein, however, the daily fluctuations were random. The behavior of daily fluctuations in UN was thus observed to be affected by the level of protein fed.N-balance serial correlation time-series analysis

The Effect of Varying Protein Levels on Carcass Composition and Nutrient Utilization in Two Lines of Chickens Divergently Selected for O2 Consumption

A replicated experiment was initiated to investigate the response of 2 populations of chickens, divergently selected for high and low O2 consumption, to varying protein levels. A 3 × 4 factorial arrangement of four isocaloric protein diets (16, 18, 22, 26%) and three levels of intake (100%, 80%, and 60% of ad libitum) were randomly assigned to 24 pens, resulting in 2 pens per treatment combination for each line. Two hundred and forty chicks from each line were then randomly assigned to the 24 pens, 10 chicks per pen. Criteria measured on a per pen basis were weekly body weight gains, daily feed intake, metabolizable energy (ME) values of the diets, and changes in carcass moisture, nitrogen, fat, and energy. Statistical analysis indicated that feed efficiency and weight gains of the low O2 birds were greater at all protein levels studied than the high O2. Carcass composition data indicated that the low O2 birds gained more lean and less fat tissue than the high O2 birds both totally and as a percentage of dry matter gain. Low O2 birds were also more efficient in the utilization of nitrogen, but there was no difference between the lines in the efficiency of ME utilization. The low O2 birds were slightly superior in net energy utilization, as would be expected since they were depositing more lean tissue. Selection for low oxygen consumption, therefore, has resulted in a faster growing, leaner, and more efficient bird.

Growth and digestibility for the green turtle ( Chelonia mydas) fed diets containing varying protein levels

Green turtles ( Chelonia mydas), age 14 or 44 months, were fed commercially prepared pelleted diets containing 25, 30 or 35% protein. Growth among the younger turtles was significantly different for the three protein levels. Growth was significantly different for the older turtles only between the 25 and 35% protein rations. Maximum observed gains were 0.5 kg and 1.0 kg per month for the 14-month and 44-month-old turtles, respectively. Dry matter digestibility of the rations and protein digestibility ranged between 80 and 90%. Protein digestibility increased with increasing protein in the diets. Analyses of gut material demonstrated that 75% of the digestion occurred in the first half of the digestive tract.

Effects of Dietary Protein on Body Weight and Reproductive Performance of Male Turkeys

Body weights and reproductive performance of Large White male breeder turkeys fed corn-soybean meal diets of varying protein levels were examined. Eight-week-old male turkeys were divided into 4 groups of 53 turkeys each and fed ad libitum diets containing 11, 13, 15, and 17% protein supplemented with methionine. Reducing dietary protein decreased feed consumption and decreased body weight gain. Semen was collected weekly from 24 turkeys in each group. At 35 weeks of age 25, 55, and 100% of the turkeys were producing semen in the 13, 15, and 17% protein groups, respectively. Semen production did not start in the 11% protein group until 42 weeks of age. The age and body weight at which 85% of the turkeys in each group were producing semen was: 28 wk, 15 kg (17% protein); 37 wk, 17 kg (15% protein); 39 wk, 15 kg (13% protein); 43 wk, 11 kg (11% protein). Semen production was maintained until the end of the experiment when the turkeys were 52 weeks old. Protein level had no effect on semen volume or sperm concentration in turkeys producing semen.During the last 10 weeks, hens were inseminated weekly with pooled semen from each group. Dietary protein level had no effect on semen fertility on the basis of 7-day-candling fertility; fertility exceeded 90% for all levels of protein.

Feed Efficiency and Gain Responses to Protein Levels in Two Lines of Birds Selected for Oxygen Consumption

Two experiments were conducted to investigate the response of two populations of chickens, divergently selected for high and low oxygen consumption, to varying protein levels. Protein levels used for Experiments 1 and 2 were 16, 18, 20, and 22% and 20, 22, 24, and 26%, respectively. The birds were weighed initially and weekly to 4 weeks of age. Feed consumption was ad libitum with amounts consumed recorded weekly. Gross feed efficiency was computed per pen as the difference between initial and weight at 4 weeks divided by feed consumed adjusted for spillage. The results from these experiments indicate that at low protein levels both lines were equally efficient, but, as the level of protein was increased, the low line was increasingly more efficient while the high line became less efficient. Gain for the low O2 birds was greater than the high O2 birds in all cases with both lines increasing in gains equally with increased protein levels.

Influence of Dietary Protein during the Pre-Breeder Period on Subsequent Reproductive Performance of Large White Turkeys: 1. Growth, Feed Consumption, and Female Sex-Limited Reproductive Traits

Large White female turkeys of a commercial variety were used to determine the effects of low dietary protein during the pre-breeder period (12 to 32 weeks of age) on subsequent reproductive performance. Diets containing 10, 12, 14, and 17% protein were fed from 12 weeks or 20 weeks to 32 weeks of age. At 32 weeks of age, all females were fed a 17% protein breeder diet. Reproductive performance was measured for a 24-week production period.Pre-breeder feed consumption and body weight gain from 12 to 32 weeks of age increased with increased dietary protein until diets contained 14% protein. Similar results were obtained when females were fed varying protein levels from 20 to 32 weeks of age.Egg production also showed an increase with increased pre-breeder dietary protein level until diets contained 14% protein. Ten fewer eggs per hen were obtained from females previously fed the 10% protein diet than those fed the 14% (20 to 32 weeks) and 17% protein diets. Pre-breeder dietary protein level did not affect age at sexual maturity, egg weight, specific gravity or shell thickness of eggs, mortality or growth, and feed consumption of progeny.Based upon the results of this study, female breeder turkeys require at least 14% protein to 20 weeks of age and 14% from 20 to 32 weeks of age for optimum egg production.

Inflammation experimentale et taux proteique alimentaire chez des rats intoxiques subchroniquement au nabame

In research on new toxicity tests, attempts have been made to measure the response to an inflammatory type of attack. Groups of rats were fed diets containing various levels of protein (0, 3·5, 9, 26 and 81% casein) or a standard laboratory chow diet, and each group was further divided into subgroups given Nabam, disodium N,N'-ethylenebis(dithiocarbamate), at a dietary level of 0, 10, 50, 100, 500, 1000 or 2000 ppm. The inflammatory response was followed in these animals by determining the levels of total mucopolysaccharides, mucopolysaccharides containing hexuronic acid, mucopolysaccharides containing N-acetylneuraminic acid, total collagen and neutrosoluble, acid-soluble, labile (at 60°C) and insoluble collagen fractions in an experimental granuloma. In animals on a normal diet, Nabam administration reduced both the fresh weight of the granuloma and the levels of these different constituents, in a dose-related manner. When the protein level of the diet was reduced, the inflammatory reaction showed a corresponding decrease, an effect clearly accentuated by Nabam; the lower the protein level, the lower the effective dose of Nabam. Nabam affected mainly the fresh weight of the granuloma expressed in relation to body weight, the levels of mucopolysaccharides, particularly the soluble fractions, and the level and distribution of collagen. This test of experimental inflammation is a sensitive method for the early detection of a toxic effect and for relating an organism's defensive capacity to its nutritional state.